The present invention relates to basket-type devices for extracting stones such as ureteral stones, calaceal stones and other calculus and the like from the renal or biliary systems.
Various types of stone extraction baskets have been used in the past to extract stones and stone fragments from various biological systems. See for example the devices shown in the following U.S. Patents: Bates U.S. Pat. No. 6,099,534, Okada U.S. Pat. No. 6,093,196, Ouchi U.S. Pat. No. 6,077,274, Bilitz U.S. Pat. No. 6,059,796, Foster U.S. Pat. No. 5,989,266, Bates U.S. Pat. No. 5,957,932, Bates U.S. Pat. No. 5,788,710, Bates U.S. Pat. No. 5,496,330, Dormia U.S. Pat. No. 4,612,931, and Segura U.S. Pat. No. 4,590,938.
A typical stone extraction basket includes a wire basket carried by one end of a wire that is received within the lumen of a sheath. The end of the wire opposite the basket is secured to a handle that is used to slide the sheath over the wire, thereby moving the basket into and out of the lumen of the sheath. When the basket is out of the sheath, it expands to receive a stone. The sheath is then moved toward the basket to reduce the size of the basket openings, and the basket and the enclosed stone are removed from the body.
Recently, ultrasonic, laser, and electro-hydraulic techniques have been used to fragment stones in situ. Typically, the stone fragments are left in the body to be excreted. However, in some cases stone fragments may not be excreted as quickly or as completely as desired. Conventional stone extraction baskets are not optimized for the extraction of shattered stone fragments. Thus, a need presently exists for an improved endoscopic stone extraction device that is easier to use and better suited for the extraction of stone fragments.
The preferred embodiments described below include a new type of handle that permits the stone extraction basket to be rotated easily inside the body by the surgeon. This rotation can be performed by the surgeon using the fingers and/or thumb of the same hand as that used to hold the handle, and the preferred embodiments are therefore single-person, single-hand operating devices. This represents a substantial advance over prior-art devices such as snares that require the use of two hands and/or two persons to operate. The preferred embodiments are readily disassembled by the surgeon when necessary to remove the handle and the associated sheath from the filament that supports the stone extraction basket. A new type of stone extraction basket is described that is well suited to the collection of small stone fragments.
The handle described below allows the basket to be rotated inside the body, as for example to orient the basket to admit a stone into the basket. The improved basket designs described below facilitate the retention and extraction of small stone fragments.
In one embodiment, the stone extraction basket has a large, side-facing opening to admit stones and stone fragments into the interior of the basket, and over half of the surface area of the basket is provided with relatively small openings adapted to retain stones and stone fragments in the basket. In another embodiment, the large openings of the basket are oriented to face the sheath, and the stone retention portion of the basket is disposed opposite the sheath.
The foregoing section has been provided by way of general introduction, and it should not be used to narrow the scope of the following claims.